Automatic immersion apparatus



July 13, 1943. a c. WEISKOPF 2,324,122

AUTOMATIC IMMERSION APPARATUS Filed Feb. 20, 1941 4 Sheets-Sheet 1 3maentor Enwm C Wm bKO'PF July 13, 19 3- a c. WEISKOPF AUTOMATIC INMERSION APPARATUS Filed Feb. 20, 1941 4 Sheets-Sheet 2 Inwm C. WmimovF (Ittomeg July 13, 1943. a c. WEISKOPF 2,324,122

AUTOMATIC IMMERSION APPARATUS Filed Feb. 20, 1941 4 Sheets-Sheet 5 Zmventor EDWI N C.WE\$\ 01 F (Ittomeg July 13, 1943.

JJ 70 6 j 136 28 I a c. WEISKOPF 2,324,122

AUTOMATIC IMMERSION APPARATUS Filed Feb. 20, 1941 4 Sheets-Sheet 4 INVENTOR.

Eowm C. WEISKOPF BY 1... are;

Patented July 13, 1943 4 UNITED STATES PATENT OFFiCE AUTOMATIC IMMERSION APPARATUS Edwin C. Weiskopf, New York, N. Y.

Application February 20, 1941, Serial No. 379,800

Claims.

This invention relates to automatic immer-= sion apparatus of the type shown in United States Letters Patent No. 2,157,875, granted to me May 9, 1939. The present invention is concerned with improvements in and additions to the apparatus disclosed in said patent.

In using the apparatus, the times of the cycles of operation vary depending upon the particular treatments to which the tissue or other material is subjected. For example, the time of the cycle of operation of the machine may vary from one day or more to one hour or less. As the timing device is preferably a unitary device including an electric motor of the electric clock type, it is advantageous to provide a plu rality of such timing devices selectively operable to control the time of the cycle of operation of the apparatus in such manner that the apparatus is operated under the sole control of the selected timing device. Thus, for example, one timing device designed to eilect the cycle of operations in a period of one day is provided with an electric clock which is effective to rotate the dish of the timing device one revolution in a period of one day while a timing device designed for a different time cycle is provided with an electric clock which is effective to rotate the timing disk one revolution corresponding to the desired period of time, for example, one hour.

It is frequently important that the periods of immersion of the tissue or other material in the several liquids or other media be accurately controlled. On the other hand, in the case of a timing device provided with a timing disk which makes a complete revolution within a relatively short time, for example, one hour, the time which passes during the actuation of the apparatus for transferring the material from one receptacle into another, there being a plurality of such transfers, is relatively large in relation to the total period of the operation of the machine, with the result that the material does not remain for the proper length'of time in each receptacle. It is, therefore, one of the objects of the present invention to obviate this objection and for that purpose to provide a. timing device which accurately determines the period during which the material is subjected to treatment in each of the receptacles and maintains the treatment for the full periods, without, however, requiring that the timing disk be rotated more than one revolution. Briefly described, this result is accomplished in accordance with the present invention by interrupting the rotation of the timing disk, preferably by interrupting the operation of the clock motor during the intervals of time when the material is being transferred from one receptacle to another. In other words, the timing disk rotates only while the material is immersed in the liquid orother media for the treatment thereof.

Provision is made in the apparatus of the above mentioned patent for immersing the tissue or other material in a paraflln bath. For obtaining a more effective impregnation of the tissue with paramn or for otherwise improving the treatment of the tissue in the paraffin bath a vacuum is provided in the paramn-bath receptacle. One of the objects of the present invention is to provide the apparatus with means for automatically subjecting the paraiiln bath to the action or a vacuum during the time the tissue is in the paraiiimbath receptacle.

A further object is to relieve the vacuum automatically preliminary to the removal of the tissue from said receptacle whereby to facilitate removal of the cover from said receptacle.

The above objects of the invention and other objects which might hereinafter appear will be more fully understood from the following description considered with reference to the accompanying drawings.

In the drawings:

Fig. 1 is a perspective view of the automatic immersion apparatus embodying the present invention;

Fig. 2 is a side view of one of the timing devices, partly in section on the line 22 of Fig. 1;

Fig. 3 is a front view of certain parts of the apparatus, the cabinet and other parts being omitted for the purpose of illustration, this figure corresponding to Fig. 6 of said Patent No. 2,157,875;

Fig. 4 is a rear view of the timing device;

Fig. 5 is a side view, partly in elevation and a partly in section of the paraffin-bath receptacle showing the tissue container positioned therein;

Fig. 6 is a view on the line 6-li of Fig. 3, and is similar to Fig. 9 of said Patent No. 2,157,875;

Fig. 7 is a circuit diagram;

Fig. 8 is a front view, on a. larger scale, of part of the timing device;

Fig.9 is a fragmentary sectional view on a larger scale on the line 98 of Fig. 1;

Fig. 10 is a vertical sectional view of part of the mechanism illustrated in Fig. 3;

Fig. 11 is a sectional view on the line ||-l| of Fig. 3;

Fig. 12 is a sectional view on the line |2l2 of Fig. 10.

Referring now to the drawings in detail, the automatic immersion apparatus of the present invention is constructed and operates substantially in the same way as the automatic. immersion apparatus shown and described in the above mentioned Patent No. 2,157,875, with the additions and modifications hereinafter described. In general, the apparatus comprises a receptacle table or support 32 mounted on top of the cabinet I0. A plurality oi'rcceptacles 38 and a re ceptacle 40 are supported on table 82 in equispaced circumferential relation. said receptacle 40 being a parafiln-bath receptacle. The rotary 'conveyor 42 is raised, turned and lowered by the 7 .8011, said cover and rod serving to support the tissue container or carrier 80 from the rim of conveyor 42. Said carrier is detachably connected to cover 48a by a bayonet-slot joint 81 (Fig. The parafiin-bath receptacle 40 is connected to a vacuum pump P operated by the electric motor PM, the conduit from said pump to said bath being indicated at 49 in Fig. 1, said con-.

duit being in the form of a tube which is connected to the nipple 49a (Fig. 5) with which the parailln bath is provided. The top or the receptacle 40 is provided with a packing ring 49b on which cover 48a is seated to provide a vacuumtight joint or fluid-sealing closure therewith. Said cover is provided with a central Opening or port 48b which, when uncovered permits air to pass into the receptacle. Said port 48b is opened and closed by a valve 480 carried by the stem 50a by which the cover 48a is connected to conveyor 42. The lower end 50b of stem 50a is provided with the valve 48c which, upon the upward movement of conveyor 42, engages the chamber-forming part 4811 fixed to said cover for moving the same pursuant to the movement of said conveyor. When cover 48a is seated .on the parafiin-bath receptacle 40, valve 480 closes opening 481). When the apparatus is actuated for removing the tissue from the paraflin bath valve 480 is raised from its seat on the cover thereby permitting air to enter the paraflln bath for breaking the vacuum therein in order to facilitate movement of cover 48a oil of the paraflin-bath receptacle, the air breaking the vacuum being supplied from chamber-forming part 48d into which the air enters in any suitable way as through the central opening 486 through which stem 50a projects. As hereinafter described the vacuum pump motor PM is actuated only at predetermined time's automatically through the control of means provided for that purpose.

The means for actuating shaft 44 to move carrier 42 vertically and rotatably will now be described. As illustrated in Figs. 3 and 10, said shaft is mounted for longitudinal and rotary movement in a guide bearing 84 having a lower circular flange 88 secured by means of bolts 10 in spaced relation above the plate or top surface I 12 of a standard 14 secured to and upstanding from the cabinet base I2. Said shaft has a reduced lower end portion 16 (Fig. 10) secured to and rotatably mounted in a cross head I8. The reduced shaft portion I6 provides a shoulder 80 which engages one end of said cross head, and

the free end of said reduced shaft portion is threaded for engagement by a nut 82 which en-- gages the other end of said cross head to fix the shaft longitudinally in relation to said cross head while permitting rotation of the shaft therein. Cross head 78 is guided for longitudinal move- Crosshead 18 and shaft 44 fixed thereto are reciprocated by a link or connecting rod 80 pivotally secured at one end 82 thereof to said cross head and pivotally secured at its other end 84 to a crank rod 88 fixed to a rotary gear 01 in any suitable way. as by screws 99. Gear 81 meshes with and is rotated by a gear I00 (Fig. 6) operated by motor M. Said motor is carried by a standard I04 fixed to and upstanding from cabinet base I2. Gear 91 is fixed to and rotates a shaft I08 (Fig. 3) which is journalled in bearings I08 and H0 on standard I04. A rotary shaft H2 is operated during the rotation of shaft I08 by gear 91 through bevelled gears H4 and H8 fixed to shafts I08 and H2, respectively. Shaft H2 is Journalled for rotation adjacent its ends in a bearing I I8 carried by standard I04 and in a bearing opening I20 formed in plate I2. As

. here shown, shaft I I2 comprises sections I22 and I24 adjustably coupled together by a coupling sleeve I28.

It will be understood that the rotation of gear 91 is effective to move shaft 44 longitudinally and also, as will now be described, rotation 01 shaft H2 is effective to cause the intermittent rotation of shaft 44. The mechanism provided for this purpose comprises 5. Geneva gear I28 (Figs. 10 and 11) which surrounds shaft 44 and through which said shaft is longitudinally movable. Said Geneva gear rests on the surface of standard plate 12 and has a bearing on said surface. Said gear is provided with a hub I30 which has a bearing in a depending flange I32 of plate I2 for rotation therein and is held against longitudinal movement by a pin I34 which is threaded in flange I32 and engages hub I30 in a peripheral groove I36. Gear I28 is provided with a plate. I38 fixed thereto. Said plate has a projection I40 which engages shaft 44 in a longitudinal groove I42 provided in said shaft whereby a rotation of gear I28 is effective to rotate shaft 44. Gear I28 is rotated by shaft II2 through a cooperating gear I44 of the Geneva gear movement. Said cooperating gear I44 i provided with a plate I48 fixed thereto and carrying a pin I48 arranged to enter the radial slots I50 of gear I28, whereby upon continuous rotation of cooperating gear I44 Geneva gear I28 is caused to rotate intermittently for a part of a revolution thereby to similarly cause shaft 44 to rotate intermittently Or to move for a corresponding part of a revolution. As here shown, gear I28 is provided with twelve radial slots I50 to accomplish twelve partial rotations of said shaft for moving carrier 42th position the holder in relation to twelve receptacles provided in the apparatus here shown, but it will be understood that the number of slots in said gear may be varied depending upon the number of different immersions or treatments to which the specimen is subjected or depending upon the intended use of the apparatus. It will be observed that cooperating. gear I44 is rotatably mounted on plate l2 andis secured to the upper end of shaft H2,

more specifically to the upper shaft section I20, by a pin I52.

From the above description, it will be understood that when gear 91 is rotated for a complete revolution upon actuation of motor M and motor gear I00, shaft 44 is moved longitudinally upwardly for the full longitudinal travel thereof and longitudinally downwardly for the full distance of its travel and that during the rotation ofgear 91 for effecting the reciprocation of shaft 44 upwardly and downwardly, shaft II2 makes one complete revolution. It will also be understood that the Geneva ear movement is such that during the initial upward movement of shaft 44 pin I48 does not engage arw of the slots I50, and cooperating gear I44 is therefore ineffective to rotate Geneva gear and shaft 44. However, when shaft 44 has been moved upwardly a suilicient distance to move holder 80 completely out of the receptacle to clear the top of the latter, pin I48 engages Geneva gear I28 in a slot I50 causing said gear and shaft 44 to rotate whereby to move holder 60 over the next receptacle. During the rotation of shaft 44 as just described the upward movement of said shaft is continued to the end of its travel and at about the time the rotary movement of said shaft is completed to center the holder Gil over the next receptacle, the shaft is moved downwardly to position the holder within said next receptacle. Thus it will be seen that the gearing arrangement is such that shaft it is actuated to raise holder Gil out of its receptacle, then to move said holder to position and center the same over the next receptacle by a partial rotation of said shaft and then to move said holder downwardly into the next receptacle whereupon the movement of the shaft is intenrupted for the time being until the next operation thereof for moving the holder out of the last mentioned receptacle and into the next receptacle.

Provision is made for balancing the upward and downward movement of the shaft M whereby to obtain a more uniform longitudinal movement of said shaft in said up and down directions. For this purpose, there is provided a countar-weight I54 (Fig. 10) guided for up and down movement on a rod I 56 fixed in standard I l. Said counter-weight I54 is connected to one end of a chain or belt I58 which passes over a rotary pulley I60 and is connected at its other end to cross head 18. Pulley ISO is mounted for rotation on a shaft or rod I62 secured at its ends in the sides I64 of standard 74. The arrange ment of the parts is such that said counterweight is raised to the limit of its upward movement when shaft 44 is at the limit of its downward movement. A set screw IE is provided for securing weight I54 against movement during shipment of the apparatus. It will be understood that shaft 44 makes one revolution during each cycle of operation of the apparatus. The intermittent operation of shaft 44 for transferring thecarrier 60 and the tissue or other material carried therein from one receptacle to another at predetermined times for subjecting the tissue to the action of the various liquids or other media in the several receptacles 38 and in the paraflin bath 4!] is controlled by timing devices which will be described presently. The timing devices are, in general, of the type illustrated in said above mentioned patent and each includes a timing disk I as disclosed therein and a finalinterruption device 260 which operates in substantially the same way as the device similarly numbered in said patent for stopping the operation of the apparatus at the end of the cycle.

A feature of the present invention is the provision of a plurality of timing devices as indicated at TI and T2 so that the operation of the apparatus can be placed selectively under the sole control of either of these timing devices. The devices have different timing characteristics, 1. e., the time of one revolution is different in each device, for example, one day in the case of timer (iii TI, and one hour in the case of time T2. It will be understood that more than two timing devices can be provided, each having a different timing characteristic. One ofthe timing devices, here shown as the timing device TI, is positioned within the cabinet ID of the apparatus, and can remain permanently in fixed position therein while the other timing device T2 is positioned exter nally or the cabinet, suitable means being provided for disconnecting one or the other of said timing devices to the companion switches and for connecting the selected timing device to said switches. As both timing devices are or can be of TI, and one hour in the case of timer T2. It will the same construction it is necessary to describe only one of them in further detail. Accordingly, referring now to Figs. 1 to 4, 8 and 9 of the drawings it will be observed that the timing device comprises a supportingpanel IIli at the heels of which is mounted an electric clock C oi the proper construction for rotating the time disk Ilii one revolution in a predetermined period of time. Said. disk ilii is a cardboard disk, suitably calibrated as described in said patent, and is carried by a plate il'lfi fixed to the shaft lid of the clock in any suitable way as by a setscrew H5. Said disk lid is secured in fixed relation to plate lit by the central part or hub Elli] of the interrupt ng device 2%, the latter being adjustably clamped in position by the head 28I of screw 282 which is threaded into the cen tral bore 283 of the hub 285 of plate H2 (Fig. 9)

The control part iil i of the arm ltd which engages successively in the notches in disk I'll! and which is engaged by the cam 262 of the interrupting device 28?] is fixed to the front end of a pivot pin I03 mounted for turning movement in a bearing portion I provided in panel mi. it switch operating arm Illl is fixed to the rear end of pin Hi3 at the back of the panel in position to actuate a. double throw micro-switch I09 mounted at the back of said panel. At the end of the operation of the apparatus arm I85 is moved by cam 262 to a retracted position in which it is held by the arm 266 which is fixed to the sleeve 26! mounted for pivotal movement on the pivot pin 212. Said sleeve has a weighted arm 214 connected thereto and tending to rotate said arm 266 so that the notched end 264 of the latter is engageable with a pin 210 fixed to arm I86. Thus, when arm I86 is moved by cam 262 arm 266 engages pin 210 for holding switch operating arm I86 in retracted position. Panel IIlI of the timer is also provided with a lamp socket II-I positioned at the back of the panel for a telltale lamp II3 contained within a protective member I I5 at the front of the panel. Also an electrical receptacle III, having a plurality of terminals, is mounted at the front of the panel for engagement with the terminals I31 and I39 of wires I31 and I39 (shown in Fig. 7) of a cable I19 by which the electric circuit including the switches thereof are placed under the control either of timer TI or T2. In other words, the terminals of cable II9 are connected to the receptacle of either timer TI or timer T2 for placing the apparatus under the control of the selected timer. An opening I2I is pro vided in the side of the cabinet to permit the cable H9 to be projected therefrom for connection to timer T2 which, as explained above, can be .connected to control the apparatus even though said timer is positioned externally of the cabinet. Opening I2I is provided so that the door 26 of the cabinet can be kept closed and locked during the operation of the apparatus. It will be understood that timer T2 may be kept in its own individual cabinet and sealed. therein by providing the cabinet with a door which can be locked to prevent tampering-with the timing device during the operation of the apparatus under its control. Thus, to place the apparatus under the control of timer T2, it is only necessary to disconnect cable II9 from timer TI and connect said cable to timer T2 by plugging the terminal end of said cable into'the terminal receptacle II1 on the timer panel of the timer T2. The

manner in which this is accomplished by means switch I25 operate jointly to control the circuit of motor M for operating shaft 44. This joint operation will be understood from an inspection of the circuit diagram shown in Fig. '1. Assuming that the timer TI is connected to the circuit for controlling the operation of the apparatus, and assuming that the operation of the apparatus is started, the part I84 of arm I86 being in a notch of the timer disk I10, a circuit is completed through motor M from one side LI of the .line through the connection IISa of the means which connects the circuit through the timer to switch I09 of said timer, the movable arm I09a of said switch being in engagement with the stationary terminal I091) which is connected to the stationary terminal I25e of switch I25. Said terminal I25a and a companion terminal I25b are bridged by a movable contact member I25e fixed to the rod I21a which is engaged and actuated by cam I21. From terminal I251) the current passes to the other side L2 of the line.

When the circuit of the motor is closed conveyor 42 is actuated for transferring the tissue carrier 60 from one receptacle to the next receptacle and during this time shaft I06 makes one revolution. At the end of the revolution of shaft I06 cam I21 actuates switch I25 through the engagement thereof with rod |2 1a for disengaging movable contact member I25e from the stationary contact members I25a and I25b and at the same time moves the movable contact member I25d of the switch into engagement with the stationary contact members I25e for bridging the latter, and simultaneously breaking the circuit through the motor and interrupting the operation of the apparatus for the time being. It will be observed that one of the terminals I25e is connected to a terminal I090 of switch I09, but at this time movable switch member I09 is out of engagement .with said terminal I090, so that the circuit is not completed through said switch when cam I21 actuates switch I25'to interrupt the same at the contacts I25a and I25b. However, during this time part I84 of arm I06 is in the notch of the timing disk I10 which continues to rotate and shortly after the actuation of switch I25 by cam I21, part I84 of arm I86 is moved out of the notch and is engaged by the edge of the disk its initial member and thereby actuates arm I. Switch "Us at this time actuated for disengagement of" the movable contact I09a thereof from contact Illb and the engagement thereof with contact Illc. thus completing the circuit of the motor through contacts I26e and said contact I090. The motor is thus effective to actuate shaft I06 but only for a fraction of a turn, 1. e., only until cam I21 disengages the switch operating member I21a permitting the spring I to move switch I25 to position for disengaging bridging I25d from stationary contacts I25e, thus again interrupting the circuit of the motor M. While bridging contact I260 is engaged with stationary contacts I25e and I25!) and the switch is thus conditioned for the next operation of the motor, the circuit through the motor is not completed since it is interrupted through the switch I09 which remains in engagement with contact I090 until subsequently operated by arm I86 when the part I94 of said arm enters into a notch brought into registry therewith when the timing disk I10 has rotated a predetermined distance. that only a small degree of rotation is necessary to disengage cam I21 from the switch operating mechanism to permit closing of contacts I25e and I25b by bridging member I25e thus placing the switching device in condition for completing the circuit through the motor when switch I09 i's ioiext actuated under the control of timing disk As explained above when the cycle of operation of the apparatus is of short duration the time consumed by the several actuations of the apparatus for transferring the tissue from one receptacle to another may constitute a substantial part of the total time of the complete cycle of operation, thus appreciably cutting down the periods during which the tissue is subjected to treatment in the several receptacles. Accordingly, a feature of the present invention resides in eliminating this objection without, however, requiring more than one revolution of the timing disk I10. In the form of the invention herein disclosed this result is accomplished by interrupting the electric clock motor of the timing device during the several aetuations of the apparatus within the cycle of operation thereof. Accordingly, provision is made for interrupting the circuit through the electric clock of the timing device during the rotation of shaft I66. The means provided for this purpose comprises a micro or other suitable switch I3I mounted in stationary position in relation to shaft I06 and provided with an actuating pin I33 adapted to be operated by a cam I35 fixed to and rotated by said shaft I06. Cam I35 is designed so that it holds switch I3I open except when shaft I06 is stationary during each of the several rest periods of the shaft actuating mechanism when the tissue is immersed in the several receptacles. Switch I3I comprises a movable spring contact member I3Ia which is biased to circuit closing position but which is held open by cam I35 during the rotation of shaft I06. Cable I I9 which connects the apparatus for control optionally under timer TI or T2 consists of wires l31, I39, 9', I09b and I09c. As shown in Fig '7, wire I39 is connected to one side LI of the line and wire I31 is connected to the other side L2 of the line through switch I 3I. Wires I31 and I39 terminate in plug-in terminals shown as switches I31 and I39, respectively, in

It will also be understood Fig. 7 and are connected optionally to the terminals I3Ia and I39a, respectively, of timer TI or to the terminals I3'Ib and I391), respectively, of timer T2. Thus, switch I3I is connected optionally to the circuit of clock TCI of timer TI or to the circuit of clock TC! of timer T2. Wire II9a' terminates in a plug-in terminal shown as a switch Him in Fig. 7, and is connected optionally either to terminal II9b of switch I09 of timer TI or to a similar terminal H90 of switch I09 of timer T2. Wire I09b' terminates in a plug-in terminal which is connected either to terminal I091) of timer TI or to the similar terminal I09b of timer T2, and Wire I090 terminates in a plug-in terminal which isconnected either to terminal I090 of timer TI or to the similar terminal I090 of timer T2 for connecting terminals Ia and I25e, respectively, of switch I25 to terminals I091) and I090, respectively, of either timer TI or timer T2. Wires M912 and I090 leading to timer T2 are shown in dotted lines in Fig. '7, since as shown in this figure of the drawings timer T2 is disconnected from the apparatus, the latter being at this time under the control of timer TI. It will be understood that receptacle I I! of each timer is provided with terminals in which said plug-in terminals of cable II!) are respectively received.

It was explained above that Whenthe tissue is immersed in the parafiin-bath receptacle 40 the interior of said receptacle has a vacuum produced therein, for which purpose a vacuum pump P is connected to said parafiin-bath receptacle. The electric motor PM for operating the vacuum pump is started and stopped automatically at predetermined times, that is, at the time the tissue is immersed in the parailin bath and at the time said tissue is removed therefrom. For accomplishing this result an automatically operated switch MI is provided in the circuit of the pump motor PM for controlling the latter. Said switch MI is mounted in stationary position on the fixed guide bearing 64 of shaft 44 and is provided with an operating pin I4Ia in position to be actuated by a member I4Ib fixed to and movable with the spider 42a of conveyor 42. Thus, when the conveyor is lowered for bringing the tissue into receptacle 40 switch MI is closed and completes the circuit through the vacuum pump motor PM. Said switch MI is biased to open position so that when the conveyor is raised for removing the tissue from the paraflin bath the circuit through the vacuum pump motor is broken thus interrupting the action of the vacuum pump. As explained above in order to facilitate removal of cover 48a from the parafiln bath-receptacle when the conveyor moves upwardly provision is made for breaking the vacuum, this being accomplished by the movement of valve 480 upwardly in chamber-forming part 48d, as illustrated in Fig. 5, when the conveyor starts to move upwardly. It will be understood that the time during which the vacuum pump motor PM operates is controlled by the timing disk I10, which is provided with a peripheral notch for this purpose. The heater for the paraifin-bath receptacle is indicated at I43 in Fig. 7.

While I have shown and described the preferred embodiment of my invention it will be understood that the latter may be embodied otherwise than as herein shown or described, and it will be also understood that in the embodiment of the invention herein disclosed certain changes may be made and will occur to skilled artisans particularly in view of my disclosure herein. Therefore, I do not wish to be limited to the invention as herein specifically illustrated or described except to the extent which may be required by the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In an automatic immersion apparatus, a plurality of receptacles, a movable carrier, intermittently operable means for moving said carrier into and out or said receptacles with intervening rest periods in said receptacles, timing means for controlling the operations of said carrier-moving means, said timing means including a motor, and means operable in response to the operation of said carrier-moving means for interrupting said motor during the periods of movements of said carrier.

2. In an automatic immersion apparatus, a plurality of receptacles, a movable carrier, intermittently operable means for moving said carrier into and out of said receptacles with intervening rest periods in said receptacles, timing means for controlling the operations of said carrier-moving means, said timing means including an electric motor and a circuit therefor, a switch for controlling the electric circuit of said motor, and means operable in response to the operation of said carrier-moving means to actuate said switch to interrupt said motor circuit during movement of said carrier and to close said circuit during said rest periods.

3. In an automatic immersion apparatus, a plurality of receptacles, a movable carrier, intermittently operable means for moving said carrier into and out of said receptacles with intervening rest periods in said receptacles, timing means for controlling the operations of said carrier-moving means, said timing means including a rotary timing member and means for rotating said timing member, and means operable to render said last mentioned means inoperative to rotate said timing member when said carrier is being moved from one container into another container.

4. In an automatic immersion apparatus, a plurality of receptacles, a movable carrier, intermittently operable means for moving said carrier into and out of said receptacles with intervening rest periods in said receptacles, timing means for controlling the operations of said carrier-moving means, and means operable under the control of said carrier-moving means for interrupting the operation of said timing means during the times when said carrier is being moved from one receptacle into another.

5. In automatic immersion apparatus comprising a plurality of receptacles, a rotary and vertically movable conveyor, a carrier supported by said conveyor and movable by the latter into and out of said receptacles with intervening rest periods during which the carrier is positioned in said receptacles, respectively, means for operating said conveyor, and means for timing the duration of said rest periods comprising a rotary disk, means for rotating said disk, and means for interrupting the operation of said disk-rotating means during the operation of said conveyor. EDWIN C. WEISKOPF. 

